Nano—or imprint lithography is used to transfer information or structures to a wafer by means of a metal or polymer stamp in that the stamp, which is provided with the corresponding information, is simply pressed into a soft auxiliary patterning layer situated on the wafer, e.g. a polymer layer, and the layer is thus correspondingly patterned. Imprint lithography, which can be used for feature sizes of around 50 nm, substantially simplifies the patterning of surfaces and can replace photolithography that is used otherwise.
The information/structures to be transferred are produced on the stamp by means of one of the known electron beam or laser lithography or optical lithography in conjunction with customary etching methods. In this case, the dimensions of the stamp correspond to those of a chip to be fabricated on the wafer. It emerges from this that the stamp in each case has to be positioned above a chip and oriented precisely. The stamp is then pressed into the auxiliary patterning layer, the information/structure being transferred into the latter. This operation is to be repeated until the entire wafer has been scanned in a manner similar to a wafer stepper.
This operation is very time-consuming and requires a precise prealignment of the wafer and then of the stamp relative to the wafer. Moreover, structures in the 50 nm range have to be realized on the stamp, which requires a very sophisticated photolithography. That leads to considerable costs, especially as the stamps are indeed subject to a certain degree of wear.